1. Field of the Invention
The present invention relates to a polarizing plate and a method of producing a polarizing plate.
2. Description of the Related Art
Polarizing films are placed on both sides of a liquid crystal cell of a liquid crystal display apparatus as a typical image display apparatus, the placement being attributable to an image-forming mode of the apparatus. For example, the following method has been proposed as a method of manufacturing the polarizing film (for example, Japanese Patent Application Laid-open No. 2000-338329). A laminate having a resin substrate and a polyvinyl alcohol (PVA)-based resin layer is stretched, and is then subjected to dyeing treatment so that the polarizing film may be formed on the resin substrate. According to such method, a polarizing film having a small thickness is obtained. Accordingly, the method has been attracting attention because of its potential to contribute to thinning of an image display apparatus in recent years.
The polarizing film can be utilized as, for example, a polarizing plate while maintaining the state of the laminate with the resin substrate. In addition, for example, a product obtained by attaching an optical functional film (such as a protective film) to the polarizing film side of the laminate and then peeling the resin substrate can be utilized as a polarizing plate. In the production of the polarizing film, adhesiveness between the resin substrate and the polyvinyl alcohol-based resin layer is preferably so high that floating or peeling does not occur therebetween at the time of treatment such as stretching or dyeing. However, when the adhesiveness between the resin substrate and the polyvinyl alcohol-based resin layer is high, peelability between the polarizing film to be obtained and the resin substrate reduces, and as a result, a peel direction, a peel angle, and the like upon peeling of the resin substrate and the polarizing film may be limited. Further, a polarizing plate using the polarizing film produced by using the resin substrate involves the following problem. A wrinkle, foreign matter, or the like is liable to occur, and hence the polarizing plate is poor in external appearance.